The casting of small parts such as dental restorations by the lost wax method is well-known. In order to produce satisfactory castings by this method it is often necessary to provide a reservoir of molten metal to compensate for shrinkage of the cast material as it cools. In addition, the additional metal insures that there are no voids such as gas or air bubbles in the casting cavity as the metal solidifies.
Where the parts to be cast are large or where only one part is desired, a single reservoir of substantial size, usually at the entrance or funnel of the investment material, will be adequate. Casting a plurality of small parts, however, requires that the reservoirs be placed close to the casting cavity.
Since the time necessary to produce a mold for lost wax casting is substantial it becomes uneconomic to cast single parts. Morever, it is highly desirable to cast as many parts as possible in the same casting operation.
Accordingly, it is an object of the present invention to provide apparatus which will facilitate the simultaneous, high quality casting of a plurality of small parts such as dental restorations.
Another object of the present invention is to provide apparatus for the casting of small parts which lends itself to a wide variety of casting requirements.
A further object of the present invention is to increase the number of small parts which may be cast in a single casting operation.
Other objects and features of the present invention will become apparent from the following description in which the parts to be cast are small dental restorations. It will be understood, however, that other small items such as, rings, buttons, settings, etc. may be cast in the hereinafter described manner without departing from the spirit of the present invention.